1. Field of Invention
The present disclosure is directed toward methods and systems for the treatment of caustic wastewater and, more specifically, to the treatment of caustic wastewater by wet air oxidation.
2. Discussion of Related Art
Wet air oxidation is a well-known technology for treating process streams, and is widely used, for example, to destroy pollutants in wastewater. The method involves aqueous phase oxidation of undesirable constituents by an oxidizing agent, generally molecular oxygen from an oxygen-containing gas, at elevated temperatures and pressures. The process can convert organic contaminants to carbon dioxide, water, and biodegradable short chain organic acids, such as acetic acid. Inorganic constituents including sulfides, mercaptides, and cyanides can also be oxidized. Wet air oxidation may be used in a wide variety of applications to treat process streams for subsequent discharge, in-process recycle, or as a pretreatment step to supply a conventional biological treatment plant for polishing.
Wet air oxidation units are in many cases operated at specific temperature and pressure ranges and sometimes with the addition of specific catalysts, depending on the nature and composition of the process stream to be treated. Operating conditions suitable for the treatment of some process streams may not be suitable for the treatment of different process streams.